<?php
//微信jssdk
namespace app\components;

use yii;
use yii\base\Component;

class GetToken extends Component{
    private $appId;
    private $appSecret;

    public function __construct() {
      $this->appId = yii::$app->params['appId'];
      $this->appSecret = yii::$app->params['appSecret'];
    }

   
    public function getAccessToken() {
      // access_token 应该全局存储与更新，以下代码以写入到文件中做示例
      $filename = Yii::$app->basePath.'/web/get_access_token.php';
      $data = json_decode($this->get_php_file($filename));
      if ($data->expire_time < time()) {
        // 如果是企业号用以下URL获取access_token
        // $url = "https://qyapi.weixin.qq.com/cgi-bin/gettoken?corpid=$this->appId&corpsecret=$this->appSecret";
        $url = "https://api.weixin.qq.com/cgi-bin/token?grant_type=client_credential&appid=$this->appId&secret=$this->appSecret";
        $res = json_decode($this->httpGet($url));
        $access_token = $res->access_token;
        if ($access_token) {
          $data->expire_time = time() + 7000;
          $data->access_token = $access_token;
          $this->set_php_file($filename, json_encode($data));
        }
      } else {
        $access_token = $data->access_token;
      }
      return $access_token;
    }

    private function httpGet($url) {
      $curl = curl_init();
      curl_setopt($curl, CURLOPT_RETURNTRANSFER, true);
      curl_setopt($curl, CURLOPT_TIMEOUT, 500);
      // 为保证第三方服务器与微信服务器之间数据传输的安全性，所有微信接口采用https方式调用，必须使用下面2行代码打开ssl安全校验。
      // 如果在部署过程中代码在此处验证失败，请到 http://curl.haxx.se/ca/cacert.pem 下载新的证书判别文件。
      curl_setopt($curl, CURLOPT_SSL_VERIFYPEER, false);
      curl_setopt($curl, CURLOPT_SSL_VERIFYHOST, false);
      curl_setopt($curl, CURLOPT_URL, $url);

      $res = curl_exec($curl);
      curl_close($curl);

      return $res;
    }

    private function get_php_file($filename) {
      return trim(substr(file_get_contents($filename), 15));
    }
    private function set_php_file($filename, $content) {
      $fp = fopen($filename, "w");
      fwrite($fp, "<?php exit();?>" . $content);
      fclose($fp);
    }

}

